Share-Based Compensation - Summary of Number of Awards Granted and Grand Date Fair Value (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets Valuation Allowance [Line Items]
Grant date fair value (in usd per share)	$ 9.44
TSR Awards
Deferred Tax Assets Valuation Allowance [Line Items]
Number of shares (in shares)	139	136	55
Grant date fair value (in usd per share)	$ 10.88	$ 9.28	$ 24.65
ROIC Awards
Deferred Tax Assets Valuation Allowance [Line Items]
Number of shares (in shares)	157	174	55
Grant date fair value (in usd per share)	$ 9.44	$ 7.93	$ 24.55